The spiral chute separator is one of the most economical gravity devices in a plant: a helical fiberglass trough that separates minerals by density and shape as slurry simply flows down it under gravity. With no motor and no reagents, it concentrates large tonnages of fine heavy minerals at very low operating cost, which is why spirals are deployed in large numbers across iron, chrome, mineral-sands and fine-gold circuits. Their simplicity also makes them well suited to remote sites with limited power and maintenance support.

How a spiral concentrates minerals

Slurry fed at the top spirals downward, and the combination of gravity, centrifugal force and the flowing water film stratifies the bed. Dense particles such as iron, chromite or gold settle and migrate to the inner edge of the trough, while lighter gangue is carried to the outer rim. Adjustable splitters near the discharge cut the band into concentrate, middlings and tailings. Because separation depends only on density and flow, the device is robust and almost maintenance-free, with no bearings or drives to service.

Where spirals fit

• Iron and chrome: as roughers and cleaners on fine fractions; central to a chrome processing plant.
• Mineral sands: recovering zircon, rutile and ilmenite from beach and dune deposits.
• Fine gold and tin: as a high-tonnage pre-concentration stage ahead of a shaking table for final cleaning.

A typical spiral start handles roughly 1 to 8 tons per hour of solids in the fine size range, usually below about 2 mm down to fine sand. Multi-start assemblies pack several intertwined troughs on one column to multiply tonnage in a small footprint, which keeps a high-capacity plant compact. The fiberglass trough with a wear-resistant lining gives long service life, and with no power draw the cost per recovered ton is among the lowest of any separator.

Part of the gravity circuit

Spirals deliver a rougher concentrate that is normally polished by a table or centrifugal concentrator, so they are designed as one stage in a balanced circuit rather than a finished-product device. Xinhai supplies spirals standalone or within a complete gravity concentration plant under our EPC+M+O model. Read our gravity concentration guide or contact us with your feed size and mineralogy for sizing.

Once ore is drilled and blasted, it has to be moved, and underground the machine that does it is the LHD loader, also called a scooptram. LHD stands for load-haul-dump: a single low-profile articulated machine scoops the broken muck pile, trams it down the heading to an ore pass, truck or stockpile, and dumps it. Its defining feature is a low, wide stance that fits the cramped cross-sections of underground development and stoping where a conventional loader could never operate.

How it works

A heavy front bucket on lift arms digs into the muck pile; the operator crowds and curls to fill, then trams with the load to the discharge point. Center articulation gives a tight turning radius in narrow drives, and a low cab and engine deck keep the overall height down. Drives are diesel for flexible, self-contained operation or electric (tethered or battery) for low-emission, low-heat working in deeper or poorly ventilated mines.

Selection logic

The main decision is bucket size, which is governed by your heading dimensions and target mucking rate. As a rule of thumb, match bucket capacity to the haul truck or ore-pass throat and to the smallest drive the machine must work in, since an oversized unit cannot turn or pass. Xinhai configures bucket capacity, machine height and width, and diesel or electric drive to your underground layout and ventilation.

• Load, haul and dump in one compact machine
• Low-profile, articulated for tight headings
• Diesel or electric drive options
• Heavy-duty bucket and arms for hard, abrasive muck

Where it fits the mining cycle

The LHD picks up directly from the muck pile produced after development drilling and blasting, and is the link between the working face and the haulage system that delivers ore to surface. Its productivity, set by bucket size and tram distance, often governs the whole mine’s mucking rate, so matching the machine to the heading and the haulage it feeds has an outsized effect on output. From there ore reports to primary crushing and on to the processing plant. Upstream, the orebody that the LHD develops is first defined by a core drilling rig.

Browse the full underground mining equipment range. For help sizing bucket capacity and drive type to your headings, contact our team.

How it works

Slurry feeds into a tank where a rotating, non-magnetic drum shell turns over a stationary magnet assembly. As magnetic particles enter the field they pin to the drum surface, are lifted clear of the slurry, and are washed off into the concentrate launder past the edge of the magnet arc. Non-magnetic and weakly magnetic material flows under and out as tailings. Field strength and drum speed are the two main levers for grade-versus-recovery.

• Low-intensity (LIMS): for strongly magnetic minerals such as magnetite; high recovery at modest field strength.
• High-intensity: for weakly magnetic minerals such as roasted hematite, ilmenite, or fine iron-bearing material that a low-intensity field would miss.

Sizing and selection

Choosing a unit starts with the magnetic susceptibility of your mineral, the feed particle size, and the required tonnage. Fine, weakly magnetic feeds need a stronger field and often a slower drum for recovery; coarse, strongly magnetic feeds run faster for throughput. As a manufacturer, Xinhai offers a range of drum diameters, widths, and magnet configurations, plus single- or multi-drum tanks, rather than one fixed model. Typical concentrate grades for magnetite circuits can reach the mid-60s percent Fe when grind and field are well matched.

Wet or dry, and where it fits

Wet separation suits fine, already-slurried feeds and avoids dust; for dry, coarse, or arid-site duty, see our dry magnetic separator, and our wet vs dry magnetic separation guide compares the two for iron ore. A wet drum unit normally works in closed circuit with grinding and classification, often after two or three cleaning passes to lift the final concentrate grade; the full magnetic separators range and our EPC+M+O service cover complete iron-ore lines from crushing to dewatering.

Send your mineral, feed size, and tonnage and we will recommend a field strength, drum configuration, and budget via our contact page.

When a gravity circuit needs a final, visually clean, smeltable concentrate, the shaking table is the device that delivers it. The Gemini 6-S style table uses a riffled deck, a controlled water film and an asymmetric back-and-forth stroke to fan out particles by density, so gold, sulfides and gangue separate into distinct bands you can split with adjustable cutters. Few other separators give you that level of visible, fine control over the final grade.

How a shaking table separates gold

Feed slurry spreads across the high corner of a slightly tilted deck. The fast-forward, slow-return stroke nudges heavy gold along the riffles toward the concentrate end, while cross-flowing wash water carries light gangue down the slope to tailings. Middlings band between the two and can be re-treated for extra recovery. Deck slope, stroke length, feed rate and wash-water volume are all tunable, which lets an operator dial in grade versus recovery for the specific feed rather than accept a fixed compromise.

Where the table sits in the flowsheet

• As a cleaner on rougher concentrate from a centrifugal concentrator, jig or spiral chute, which is the most common duty.
• As a primary concentrator for small alluvial or hard-rock free-gold operations.
• For recovering tungsten, tin, tantalum and other heavy minerals where the density contrast is high.

A single deck handles roughly 0.1 to 1.5 tons per hour depending on size and feed, and multi-deck arrangements multiply throughput in a small footprint. Because the separation is visible, the table doubles as a process check; operators can see at a glance whether the upstream circuit is liberating and recovering gold properly, which makes it a useful diagnostic as well as a concentrator. Wear is limited mainly to the deck surface and riffle covering, so running cost is low and predictable.

Sized into your circuit

Tables are chosen by feed size, throughput and how clean the final concentrate must be, and they usually run after a rougher stage rather than alone. Xinhai supplies them individually or as part of a complete gravity concentration circuit under our EPC+M+O model. Read our gravity concentration guide or contact us with your feed details for sizing.

The standard copper flotation circuit

A typical copper circuit runs in stages so that grade and recovery can be optimized together:

1. Rougher: recovers the bulk of the copper at a lower grade from fresh feed.
2. Scavenger: recovers remaining values from rougher tailings to push recovery up.
3. Cleaner (one or more stages): re-floats the rougher concentrate to lift grade to a salable level, often 20-30% Cu.

Reagent scheme matters as much as cells. Xanthate or dithiophosphate collectors target copper sulfides, lime controls pH (commonly 9-11 to depress pyrite), and a frother stabilizes the froth. We bench-test your ore to set the scheme before fixing cell volumes.

Equipment and sizing

The plant is built from mechanical flotation machines arranged into banks, fed by upstream wet grinding and classification. Cell number and volume are set by feed tonnage, required residence time, and float kinetics. As an OEM manufacturer, Xinhai scales the circuit from small operations to large concentrators rather than offering one fixed size. Typical copper recovery falls in the 85-95% band, with the exact figure driven by liberation, oxidation, and clay content.

From flowsheet to commissioning

A flotation plant rarely stands alone; it sits between grinding and dewatering and is best delivered as part of an integrated line through our EPC+M+O service, from ore testing and flowsheet design through manufacturing, installation, and operator training. Buying the circuit single-source keeps the grinding, flotation, and dewatering interfaces clean and shortens commissioning. For the wider context of cell types and circuit logic, see the flotation cells and machines category and our copper ore beneficiation flowsheet guide.

Share your ore grade, mineralogy, and target throughput and we will propose a circuit, expected grade-recovery, and budget. Begin on our contact page.

How it works

Material drops onto a rotating grinding table where spring-loaded rollers press it against a stationary ring. An upward air stream lifts the ground powder into an integral classifier; particles at target fineness pass through to the cyclone and bag collector, while oversize falls back for regrinding. The result is a tightly controlled product distribution with low residue.

• Adjustable fineness: typically 80-325 mesh, up to roughly 400 mesh on softer minerals.
• Dry, closed-circuit operation: no slurry, no dewatering step.
• Integrated classifier and dust collection for a clean, compact line.

Selection and sizing

Three variables drive mill selection: feed hardness and moisture, target fineness, and required output. Softer minerals at coarser settings give the highest throughput; pushing fineness toward 325-400 mesh lowers capacity, so the classifier speed and roller pressure are tuned accordingly. Feed moisture should generally stay under about 6% for stable airflow. As a manufacturer, Xinhai offers a range of roller numbers and ring diameters rather than one model, so capacity and motor power are matched to your powder spec.

For minerals that are too hard or that need a wet flowsheet, a tumbling mill is the better tool; see our wet ball mill and the wider ball mills and grinding machines category. To understand where grinding sits relative to classification, our guide on choosing a grinding mill covers the circuit logic.

Wear parts and operating cost

The main consumables are the roller sleeves and grinding ring, both made from wear-resistant alloy and stocked as spares. Because the mill runs dry with internal classification, operating cost is driven mainly by power and wear-part replacement rather than reagents or water. Energy-efficient design and a well-tuned classifier keep specific energy competitive for fine powder duties.

Tell us your mineral, feed size, target mesh, and tonnage, and we will recommend a configuration with budget and lead time. Start the conversation on our contact page.

Spodumene is the dominant hard-rock lithium mineral, and turning a 1 to 1.5 percent Li2O ore into a marketable 5.5 to 6 percent Li2O concentrate takes a carefully staged flowsheet rather than a single machine. Xinhai designs and supplies complete spodumene lines, with a 1,000 tpd configuration as a common starting point, scaled up or down to suit your reserve grade, mineralogy and product specification. Each stage is balanced so the plant hits the concentrate grade buyers and converters demand.

A typical spodumene flowsheet

After crushing and screening, many spodumene ores benefit from dense-media separation (DMS) to reject low-grade coarse waste cheaply before fine grinding, which is where most of the energy cost sits. The DMS concentrate and middlings are then ground and treated by flotation, where conditioned reagents float spodumene away from feldspar, quartz and mica. Magnetic separation removes iron-bearing minerals to meet the low-iron spec that converters require, and the concentrate is thickened and dewatered for shipping while process water is recovered and recycled.

DMS plus flotation, sized to the ore

• DMS pre-concentration: rejects coarse barren rock early, cutting downstream grinding and flotation load and lowering reagent cost.
• Grinding: liberation typically targets a fine grind so spodumene floats cleanly; the exact size comes from ore testing, not a generic rule.
• Flotation: upgrades to a 5.5 to 6 percent Li2O concentrate, with recoveries commonly in the 75 to 90 percent range on suitable ore.
• Iron removal: magnetic separation trims iron to meet battery- or technical-grade limits.

Mica and iron content are the two specs that most often decide whether a concentrate is saleable, so the cleaner and magnetic stages are designed around them rather than bolted on afterward. Reagent regime and grind size are confirmed on your own ore in the lab before any equipment is sized.

Delivered as one EPC scope

Lithium projects move fast, and a single-source plant keeps the DMS, grinding, flotation and dewatering stages balanced as one design with one party accountable. Under our EPC+M+O model, Xinhai handles ore characterization, flowsheet and plant design, in-house manufacturing, installation and operator training. Explore our mineral processing plants, read the spodumene processing flowsheet guide, or contact us with your ore data.

Chromite carries a high specific gravity (around 4.3 to 4.6) against the silicate gangue around it, which makes gravity concentration the workhorse route for chrome. Xinhai designs and builds the full plant, alluvial or hard-rock, as a single EPC scope so the scrubbing, sizing and separation stages all match the way your chromite is liberated. Because gravity needs no reagents, the operating cost per ton stays low, which matters on the often-modest grades that chrome deposits carry.

A typical chrome flowsheet

Run-of-mine ore is scrubbed and washed to break down clay, then screened into size fractions, since each separator works best within a narrow size band. Coarse material reports to jigging, while the finer fractions are concentrated on spiral chute separators and cleaned on shaking tables. Hard-rock chromite first passes through crushing and grinding to liberate the chromite grains before the same gravity train upgrades it. Dewatering and water recovery close the circuit so the plant can run on a tight water balance.

Alluvial versus hard-rock

• Alluvial chrome: already liberated, so the plant centers on washing, screening and gravity separation with minimal comminution and lower capital cost.
• Hard-rock chrome: needs crushing and grinding ahead of gravity to free the chromite grains; the grind size is set by liberation testing rather than guesswork.

On suitable feed, gravity concentration typically lifts chromite to a 40 to 46 percent Cr2O3 saleable concentrate with stage recoveries in the 85 to 95 percent band. The chrome-to-iron ratio of the product is just as important to buyers as the Cr2O3 grade, so we design the circuit with that specification in mind. Where iron-bearing gangue limits the gravity grade, a magnetic cleaning stage can be added; we evaluate that during flowsheet design.

Built and supported as one scope

Buying the chrome plant as a single engineered package keeps the mass balance, water balance and equipment ratings consistent from feed bin to product stockpile, with one party accountable for the result. Under our EPC+M+O model, Xinhai runs the ore testing, design, in-house manufacturing, installation and operator training. See the full range of mineral processing plants or send us your chrome assay for a sized proposal.

The PE jaw crusher is the workhorse of primary crushing. It takes run-of-mine ore straight from the vibrating grizzly feeder and reduces oversize rock to a manageable size before it moves to secondary crushing. In most hard-rock circuits it is the first machine ore touches, so reliability and a generous feed opening matter more than fine sizing here.

How it works

Material drops into a V-shaped chamber formed by a fixed jaw plate and a moving jaw driven by an eccentric shaft and toggle. As the moving jaw advances, rock is compressed and fractured; as it retreats, the broken product falls toward the discharge. The closed-side setting (CSS) is adjusted with shims or a wedge to control product size.

Selection logic

Two numbers drive jaw crusher selection: maximum feed size and required throughput. As a rule of thumb, feed should not exceed about 80% of the gape. A PE-400×600, for example, accepts feed to roughly 340 mm; larger PE-900×1200 frames take feed near 750 mm and push higher tonnage. Xinhai sizes the frame, motor and CSS range to your ore hardness and target product, since abrasive ores such as quartz-bearing gold rock wear plates faster than softer limestone.

• Primary reduction ahead of cone or impact crushing
• Adjustable CSS for a controlled product top size
• High-manganese jaw plates that reverse to double service life
• Heavy flywheels to smooth load on the eccentric shaft

Wear parts and operating cost

The main wear items are the fixed and moving jaw plates and the cheek plates lining the chamber. Mn13Cr2 or Mn18 castings are standard; plate life depends on ore abrasiveness and feed rate. Keeping the chamber choke-fed and avoiding tramp metal protects the toggle, which is designed as a sacrificial safety link.

After primary reduction, product typically reports to a spring cone crusher for secondary or fine crushing, then to screening and grinding. Browse the full crushing machinery range, or see how crushing fits a complete plant in our CIP gold processing plant. For sizing help, contact our engineers with your ore and tonnage targets.

For small and mid-scale gold projects, a packaged CIP plant is often the fastest route from ore to dor. Xinhai’s 120 tpd configuration brings together grinding, cyanide leaching, carbon-in-pulp adsorption and the gold room into one engineered line, pre-balanced so the leach time, carbon inventory and tank sizing all match a 120-ton-per-day feed. The same design scales from roughly 50 up to 500 tpd, so a project can start modest and expand without re-engineering the whole flowsheet.

How the CIP circuit recovers gold

Crushed ore is ground to a liberation size, commonly 70 to 80 percent passing 75 microns, and conditioned to a controlled pulp density. The pulp leaches in a train of double-impeller agitation tanks, then flows through separate carbon adsorption tanks where activated carbon captures the dissolved gold counter-current to the slurry, with inter-stage screens holding the carbon back as pulp advances. Loaded carbon goes to elution and electrowinning, and stripped carbon is regenerated in a kiln and recycled back to adsorption.

Why CIP for this scale

• Suits free-milling, low-clay ores with fast leach kinetics and low preg-robbing tendency.
• Separating leaching from adsorption keeps carbon management simple and inter-stage screens cleaner.
• For slow-leaching or carbonaceous ores, a CIL variant may recover more; we test and advise.

On suitable ore, this line typically returns 90 to 96 percent gold recovery. Reagent dosing, aeration and carbon movement are tuned during commissioning to hold recovery while keeping cyanide and energy cost per ounce in check, and operators are trained to read those levers during ramp-up. A defined spares list and wear schedule keep the small plant running with minimal downtime, which matters most where a remote site cannot wait on parts.

Turnkey, and ready to scale

Because it ships as one EPC scope, the 120 tpd plant arrives mass-balanced and water-balanced rather than assembled from mismatched parts, and a single party stays accountable for the agreed grade and recovery. Under our EPC+M+O model we handle ore testing, flowsheet design, in-house manufacturing, on-site installation and operator training, then stay through ramp-up. Compare it with the full-scale CIP gold plant, read our small-scale gold plant guide, or contact us for a quote.